fix(actions): update to jdk 21

Author: ChachyDev

.github/workflows/build.yml

@@ -7,10 +7,10 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v2
-      - name: Set up JDK 17
+      - name: Set up JDK 21
         uses: actions/setup-java@v2
         with:
-          java-version: '17'
+          java-version: '21'
           distribution: 'adopt'
       - uses: actions/cache@v2
         with: